Lamp assembly having terminal pins for engaging external circuit connectors

ABSTRACT

An assembly for mounting a plurality of lamps in readout devices, illuminated switches, indicators, and the like. In one embodiment, each lamp is electrically connected to a flanged base and to a terminal pin insulated from and projecting from the base. The lamps are positioned in openings through a conductor carrying lamp mounting plate. The lamp terminal pins, and a common terminal connected to the conductor on the mounting plate, project through openings in a base plate which is releasably attached to the mounting plate for changing the lamps. In a second embodiment, lamps having conventional flanged bases are positioned in openings in the mounting plate and headed terminal pins are mounted in the base plate such that the pin heads contact the lamps. In both embodiments, a plurality of elastomeric rings, one placed on each terminal pin, are compressed between the lamps, or the terminal pin heads, and the base plate to urge the lamp base flanges into electrical contact with the conductor on the lamp mounting plate. The terminal pin openings in the base plate are slightly enlarged so that the terminal pins can move to a small extent to align with an external circuit connector.

O United States Patent 1 1 3 Leslie et al. 1 May 2, 1972 54] LAMPASSEMBLY HAVING TERMINAL 2,890,445 6/1959 Korry ..340/378 A PINS FORENGAGING EXTERNAL 3,518,619 6/1970 De Lano ..339/127 R CIRCUITCONNECTORS Primary Examiner-David Schonberg [72] Inventors: Warren A.Leslie; Rudolf Welnhart, both AssislantExaminer-Toby H. Kusmer ofInglewood, Calif. Attorney-Owen & Owen [73] Assignee: Master SpecialtiesCompany, Costa Mesa, [57] ABSTRACT Cam- An assembly for mounting aplurality of lamps in readout Filed: y 1970 devices, illuminatedswitches, indicators, and the like. In one [2]] APpL No: 54,166embodiment, each lamp is electrically connected to a flanged base and toa terminal pin insulated from and projecting from the base. The lampsare positioned in openings through a con- [52] U.S. Cl ..3l3/3l8,339/126, 339/176 L, ductor carrying lamp mounting plate. The lampterminal pins, 340/324, 340/366 G, 340/378 A and a common terminalconnected to the conductor on the [51] lnt. Cl. ..H01j 5/48, HOlj 5/50mounting plate, project through openings in a base plate [58] Field ofSearch ..313/3 1 8; 340/324 R, 366 G, which is releasably attached tothe mounting plate for chang- 340/378 R, 378 A; 339/126, 127 R, 59 L,176 L, ing the lamps. in asecond embodiment, lamps having conven- 144145 tional flanged bases are positioned in openings in the mountingplate and headed terminal pins are mounted in the base [56] ReferencesCited plate such that the pin heads contact the lamps. In bothembodiments, a plurality of elastomeric rings, one placed on each UNlTEDSTATES PATENTS terminal pin, are compressed between the lamps, or theterminal pin heads, and the base late to ur e the lam base 3328926 H1966Coronado-Ame "340/378 A flanges into electrical contact wit h the condtictor on th? lamp 430,437 6/1890 Rockwell ..339/144 mounting plate. Theterminal pin openings in the base plate l-lallerberg.... G are enlargedso h the terminal pi can move to a 3,530,330 9/1970 Dupree 3/318 smallextent to align with an external circuit connector. 3,522,600 8/1970Amis et al. .....340/378 R 3,] 10,620 1 1/1963 Abendroth ..340/378 A 17Claims, 4 Drawing Figures Patented May 2, 1972 mmm T mum ,T q m g m H W"W LAMP ASSEMBLY HAVING TERMINAL PINS FOR ENGAGING EXTERNAL CIRCUITCONNECTORS BACKGROUND OF THE INVENTION This invention relates to lampassemblies and more particularly to an improved assembly for mounting aplurality of lamps in readout devices, illuminated switches, indicators,and the like.

Lamp assemblies are used in various devices to mount one or moreelectric lamps and to make the necessary electrical connections to themounted lamps. Miniaturization of many electrical devices has presentedproblems in mounting lamps for ease of replacement, while maintainingreliable electrical connections to the lamps. These problems areparticularly serious in readout devices, such as warning and messageindicators, segment type readout devices and projection type readoutdevices, because each of these devices typically includes several smalllamps mounted in a closely spaced rela tionship. Furthermore, readoutdevices of this type are often used in critical circuits, such as incomputer control panels and in aircraft and military controls, wherefaulty lamps must be quickly replaced. In the past, miniature andsub-miniature lamps have usually had either wire leads or flanged basesfor connection to an external circuit. The wires, which are soldered toor wrapped around terminals, provide a reliable electrical connection.However, lamps with wire lead connections are difficult to replace.Lamps having flanged bases are easier to replace. However, electricalcontact is typically made through a small spring terminal which issubject to failure. When, for example, the lamp has a diameter on theorder of one-eighth inch and as many as 16 lamps are mounted in athree-quarter inch by five-eighth inch space, it is difficult to mountsixteen small, yet reliable spring terminals in such a confined space.If any spring terminal or lamp base becomes dirty or oxidized, aresistive contact can occur between the terminal and the lamp, resultingin a failure.

SUMMARY OF THE INVENTION According to the present invention, an improvedassembly is provided for removably mounting a plurality of lamps inelectrical devices. In one embodiment of the invention, each lampincludes a bulb which is attached to a flanged base and to a terminalpin. Electrical connections are made from the bulb to the base and tothe terminal pin which is projecting from, and insulated from, the base.The flanged lamp bases are received by openings in a conductor carryingmounting plate, such as a copper clad circuit board. A base plate havingopenings for passing the lamp terminal pins is releasably attached tothe mounting plate. A nonconducting, elastomeric ring is positioned oneach lamp terminal pin between the lamp base and the mounting plate. Theelastomeric ring may, for example, comprise either an O-ring or a ringmolded in place. When the base plate is attached to the mounting plate,each elastomeric ring is compressed between the lamp base and the baseplate, forcing the flanges on the lamp bases into electrical contac twith the conductor on the mounting plate. The conductor is in turnconnected to a common terminal. The terminal pin openings in the baseplate are sufficiently large that the pins will move to self-align withan external circuit connec tor. One or more of the lamps can be quicklyreplaced by simply removing the external circuit connector and the baseplate and lifting the loose lamps from the mounting plate.

In a second embodiment of the invention, lamps having conventionalflanged bases with a center contact are used in the lamp assembly. Theflanged lamp bases are again positioned in openings in a conductorcarrying mounting plate, with the base flanges contacting the conductor.A plurality of headed terminal pins are positioned in openings in a baseplate such that each pin head will align with a center contact on adifferent lamp. At least one, and preferably two, elastomeric rings areplaced on each terminal pin. The base plate is then releasably attachedto the mounting plate with the rings compressed between the pin headsand the base plate. The rings exert a sufficient force to maintainelectrical and mechanical contact between each terminal pin head and theadjacent lamp center contact and between the lamp base flanges and theconductor on the mounting plate. The pin openings in the base plate aresufficiently large that the pins can move to align with an externalcircuit connector. When two elastomeric rings are placed on a terminalpin, one is preferably recessed into the base plate to retain the pinwith the base plate while the base plate is removed for lamp replacementand to form a seal for preventing passage of dust and moisture.

Accordingly, it is a primary object of this invention to provide animproved lamp assembly for releasably mounting a plurality of lamps.

Another object of the invention is to provide an improved assembly forreleasably mounting a plurality of closely spaced lamps in readoutdevices, illuminated switches, indicators, and the like.

Other objects and advantages of the invention will become apparent fromthe following detailed description, reference being made to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view ofa readout device embodying an improved lamp assembly according to theinstant invention;

FIG. 2 is a side elevational view, in partial section, of the readoutdevice of FIG. 1, showing the lamp assembly in detail;

FIG. 3 is an enlarged sectional view of a lamp showing the attachmentsto the flanged base and the terminal pin; and

FIG. 4 is a side elevational view, in partial section, of a modifiedembodiment of a lamp assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 and 2,a readout device 10 is shown embodying a lamp assembly 1 1 according tothe instant invention. The readout device 10 is of a segment typewherein each segment 12 is defined by ends 13 of a plurality of fiberlight guides 14. The fiber light guides 14 for each segment have secondends 15 which are bundled together adjacent a lamp 16. When the lamp 16is energized, light passes through the guides 14 and is emitted from theguide ends 13 to define a brightly illuminated segment 12. By energizingpreselected combinations of the lamps 16, the seven segments 12 may beilluminated to form the digits one through nine and zero.

Although the lamp assembly 11 is shown embodied in a segment typereadout device 10, it is to be understood that the lamp assembly 11 maybe embodied in other types of readout devices. For example, the lampassembly 11 may be embodied in a projection type readout device as shownin Hollowich et al. US. Pat. No. 3,096,512 or in a warning indicatordevice such as is shown in Hallerberg US. Pat. No. 3,090,949. Thedisclosures of the Hollowich et al., and Hallerberg patents areincorporated herein.

Referring now to FIG. 3, the lamp 16 comprises a bulb I7 having wireleads 18 and 19, a tubular base 20 having an annular flange 21, aninsulator sleeve 22, and a terminal pin 23. The base 20 is formed of aconductive material such as brass and has either the same or a slightlylarger outer diameter as the bulb 17. The insulator sleeve 22 isdesigned to slide into the base 20 with the lead 18 pinched between theinsulator sleeve 22 and the base 20. A flange 24 on the insulator sleeve22 prevents the sleeve 22 from moving too far into the base 20. An end25 of the terminal pin 23 is similarly pressed into the insulator sleeve22, with the lead 19 pressed between the sleeve 22 and the pin end 25. Aflange 26 on the pin 23 limits axial movement of the pin 23 into theinsulator sleeve 22. Sufficient pressure is exerted on the leads 18 and19 to maintain electrical contact between the lead 18 and the base 20and between the lead 19 and the pin end 15 without soldering or weldingthe leads I8 and 19. Void spaces within the base 20 are filled with asuitable cement, such as an epoxy resin, to bond the bulb 17 to the base20, the insulator sleeve 22 and the pin 23.

Turning again to FIG. 2, one embodiment of a lamp assembly 11 is shownin detail. The lamp assembly 11 generally comprises a mounting plate 28having an electrical conductor 29 attached thereto and a base plate 30.The mounting plate 28 and conductor 29 may, for example, consist of acopper clad printed circuit board or a plate molded from a syntheticresinous material with a conductor attached thereto. The lamps 16 areinserted into openings 31 in the mounting plate 28. The openings 31 aresufficiently large as to pass the lamp bases 20, while blocking passageof the flanges 21. All of the lamp base flanges 21 electrically contactthe conductor 29, which is connected to a common terminal 32. Anelastomeric ring, such as a conventional O-ring 33, is placed on theterminal pin 23 for each lamp 16 to function as a spring. When the baseplate 30 is attached to the mounting plate 28 by means of one or morescrews 34 or with other suitable attaching means, the O-ring 33 on eachlamp terminal pin 23 is compressed against the base plate 30, therebyurging the lamp base flange 21 into mechanical and electrical contactwith the conductor 29. The screws 34 or other attaching means releasablyengage the mounting plate 28 to allow removal of the base plate 30 forreplacing the lamps 16. The base plate 30 has a plurality of openings35, one for passing each lamp terminal pin 23. The openings 35 arepreferably larger in diameter than the diameter of the pins 23, allowingthe lamps 16 to move slightly for aligning the pins 23 with an externalcircuit connector (not shown). The lamp assembly 11 is also providedwith a plate 36 positioned about the bulb 17 of each of the lamps 16.The plate 36 is formed of aluminum, or other suitable heat conductivematerial, and functions as a heat sink to cool the lamps 16. Referringnow to FIG. 4, a readout device 40 is shown with a modified lampassembly 41. The lamp assembly 41 is adapted for use with a conventionallamp 42 having a flanged base 43 and a center contact 44. The flangedlamp base 43 contacts a conductor 45 which is attached to a mountingplate 46. The lamp center contact 44 is in electrical contact with aheaded end 47 of a terminal pin 48. The terminal pin 48 passes throughan opening 49 in a base plate 50. Again, the opening 49 in the baseplate 50 is slightly larger than the diameter of the terminal pin 48,allowing the terminal pin 48 to move into alignment with an externalcircuit connector 51. Two O-rings 52 and 53 are shown positioned on theterminal pin 48. The rings 52 and 53 are compressed between the headedend 47 of the terminal pin 48 and the base plate 50 to urge the pin head47 into electrical contact with the lamp contact 44 and the flanged lampbase 43 into electrical contact with the conductor 45. The conductor 45,which is connected to all of the lamp bases 43, is connected to a commonterminal 54. The base plate 50 includes a resilient arm portion 55 whichterminates into a catch 56 for releasably engaging the readout device40. By releasing the catch 56, the base plate 50 is removed from thereadout device 40 for replacing the lamps 42. The O-rings 53 on theterminal pins 48 are recessed into the base plate 50 to serve thefurther functions of sealing the terminal pins 48 to the base plate 50against passage of dust and moisture, and of holding the terminal pins48 in the base plate 50 when the base plate 50 is removed from thereadout device 40. Although two O-rings 52 and 53 are shown in FIG. 4,it is readily apparent that other similar types of elastomeric rings maybe used. Elastomeric material can, for example, be molded into generallyflat washers or into short tubular pieces for replacing the O-rings.

It will be appreciated that various modifications and changes may bemade in the lamp assembly and in devices in which the lamp assembly isincorporated without departing from the spirit and the scope of theappended claims.

What we claim is:

1. A lamp assembly comprising, in combination, a plurality of lamps,each having electrical connections to a flanged base and to a terminalpin projecting from said base, said terminal pin being electricallyinsulated from said lamp base, a common terminal, a lamp mounting platehaving a plurality of openings for receiving and supporting saidplurality of lamp bases, means electrically connecting said lamp basesto said common terminal, a plurality of springs, at least one springpositioned on each lamp terminal pin, an electrically nonconducting baseplate having a plurality of openings for passing said lamp terminal pinswhereby each of said lamp terminal pins is in position to engage anexternal circuit connector, and means for releasably connecting saidbase plate to said lamp mounting plate, said springs being compressedbetween said base plate and said lamps when said base plate is connectedto said lamp mounting plate.

2. A lamp assembly, as defined in claim 1, wherein said means connectingsaid lamp bases to said common terminal comprises an electricallyconductive layer attached to said lamp mounting plate, said springsurging said flanged lamp bases into electrical contact with said layeron said mounting plate.

3. A lamp assembly, as defined in claim 2, wherein said springs areelastomeric O-rings.

4. A lamp assembly, as defined in claim I, wherein said springs areelastomeric O-rings.

5. A lamp assembly, as defined in claim 1, wherein said springs areelastomeric rings.

6. A lamp assembly, as defined in claim 1, wherein said means forreleasably connecting said base plate to said lamp mounting plateincludes at least two retaining screws.

7. A lamp assembly, as defined in claim 1, wherein said means forreleasably connecting said base plate to said lamp mounting plateincludes snap means.

8. A lamp assembly, as defined in claim 1, wherein the terminal pinopenings in said base plate are larger than the diameters of saidtenninal pins, whereby said terminal pins can move to align with anexternal circuit connector.

9. A lamp assembly comprising, in combination, a plurality of lamps,each lamp having electrical connections to a flanged base and to aterminal insulated from said base, a common terminal, a lamp mountingplate having a plurality of openings for receiving and supporting saidplurality of lamp bases, means electrically connecting said lamp basesto said common terminal, an electrically nonconducting base plate, meansfor releasably connecting said base plate to said mounting plate, aplurality of headed terminal pins, said terminal pins being positionedin openings through said base plate with the head of each pin inelectrical contact with a lamp terminal and wherein the other end ofeach of said terminal pins is in position to engage an external circuitconnector, and a plurality of elastomeric rings, at least oneelastomeric ring positioned on each terminal pin, each elastomeric ringbeing compressed between the terminal pin head and said base plate tourge such pin head into electrical contact with a lamp terminal.

10. A lamp assembly, as defined in claim 9, wherein said elastomericrings are O-rings.

11. A lamp assembly, as defined in claim 9, wherein said meansconnecting said lamp bases to said common terminal comprises anelectrically conductive layer attached to said lamp mounting plate, saidelastomeric rings urging said flanged lamp bases into electrical contactwith said layer on said mounting plate.

12. A lamp assembly, as defined in claim 11, wherein the terminal pinopenings in said base plate are larger than the diameters of saidterminal pins, whereby said terminal pins can move to align with anexternal circuit connector.

13. A lamp assembly, as defined in claim 12, wherein two elastomericrings are mounted on each terminal pin, one of said two rings on eachterminal pin engaging a recess on said base plate to retain saidterminal pins when said base plate is released from said mounting plate.

14. A lamp assembly comprising, in combination, a lamp having electricalconnections to a flanged base and to a terminal pin projecting from saidbase, said terminal pin being electrically insulated from said lampbase, a common terminal, a lamp mounting plate having an opening forreceiving and supporting said lamp base, means electrically connectingsaid lamp base to said common terminal, a spring, said spring beingpositioned on said lamp terminal pin, a base plate having an opening forpassing said lamp terminal pin whereby an end of said lamp terminal pinis in position to engage an external circuit connector, and means forreleasably connecting said base plate to said mounting plate, saidspring being compressed between said base plate and said lamp when saidbase plate is connected to said mounting plate.

15. A lamp assembly, as defined in claim 12, wherein said spring is anelastomeric O-ring.

16. A lamp assembly comprising, in combination, a lamp having electricalconnections to a flanged base and to a terminal insulated from saidbase, a common terminal, a lamp mounting plate having an opening forreceiving and supporting said lamp base, means electrically connectingsaid lamp base to said common terminal, a base plate, means forreleasably connecting said base plate to said mounting plate, a headedterminal pin, said terminal pin being positioned in an opening throughsaid base plate with said pin head in electrical contact with said lampterminal and wherein an end of said terminal pin is in position toengage an external circuit connector, and at least one elastomeric ringpositioned on said terminal pin, said elastomeric ring being compressedbetween said terminal pin head and said base plate to urge said pin headinto electrical contact with said lamp terminal.

17. A lamp assembly, as defined in claim 16, wherein said elastomericring is an O-ring.

1. A lamp assembly comprising, in combination, a plurality of lamps,each having electrical connections to a flanged base and to a terminalpin projecting from said base, said terminal pin being electricallyinsulated from said lamp base, a common terminal, a lamp mounting platehaving a plurality of openings for receiving and supporting saidplurality of lamp bases, means electrically connecting said lamp basesto said common terminal, a plurality of springs, at least one springpositioned on each lamp terminal pin, an electrically nonconducting baseplate having a plurality of openings for passing said lamp terminal pinswhereby each of said lamp terminal pins is in position to engage anexternal circuit connector, and means for releasably connecting saidbase plate to said lamp mounting plate, said springs being compressedbetween said base plate and said lamps when said base plate is connectedto said lamp mounting plate.
 2. A lamp assembly, as defined in claim 1,wherein said means connecting said lamp bases to said common terminalcomprises an electrically conductive layer attached to said lampmounting plate, said springs urging said flanged lamp bases intoelectrical contact with said layer on said mounting plate.
 3. A lampassembly, as defined in claim 2, wherein said springs are elastomericO-rings.
 4. A lamp assembly, as defined in claim 1, wherein said springsare elastomeric O-rings.
 5. A lamp assembly, as defined in claim 1,wherein said springs are elastomeric rings.
 6. A lamp assembly, asdefined in claim 1, wherein said means for releasably connecting saidbase plate to said lamp mounting plate includes at least two retainingscrews.
 7. A lamp assembly, as defined in claim 1, wherein said meansfor releasably connecting said base plate to said laMp mounting plateincludes snap means.
 8. A lamp assembly, as defined in claim 1, whereinthe terminal pin openings in said base plate are larger than thediameters of said terminal pins, whereby said terminal pins can move toalign with an external circuit connector.
 9. A lamp assembly comprising,in combination, a plurality of lamps, each lamp having electricalconnections to a flanged base and to a terminal insulated from saidbase, a common terminal, a lamp mounting plate having a plurality ofopenings for receiving and supporting said plurality of lamp bases,means electrically connecting said lamp bases to said common terminal,an electrically nonconducting base plate, means for releasablyconnecting said base plate to said mounting plate, a plurality of headedterminal pins, said terminal pins being positioned in openings throughsaid base plate with the head of each pin in electrical contact with alamp terminal and wherein the other end of each of said terminal pins isin position to engage an external circuit connector, and a plurality ofelastomeric rings, at least one elastomeric ring positioned on eachterminal pin, each elastomeric ring being compressed between theterminal pin head and said base plate to urge such pin head intoelectrical contact with a lamp terminal.
 10. A lamp assembly, as definedin claim 9, wherein said elastomeric rings are O-rings.
 11. A lampassembly, as defined in claim 9, wherein said means connecting said lampbases to said common terminal comprises an electrically conductive layerattached to said lamp mounting plate, said elastomeric rings urging saidflanged lamp bases into electrical contact with said layer on saidmounting plate.
 12. A lamp assembly, as defined in claim 11, wherein theterminal pin openings in said base plate are larger than the diametersof said terminal pins, whereby said terminal pins can move to align withan external circuit connector.
 13. A lamp assembly, as defined in claim12, wherein two elastomeric rings are mounted on each terminal pin, oneof said two rings on each terminal pin engaging a recess on said baseplate to retain said terminal pins when said base plate is released fromsaid mounting plate.
 14. A lamp assembly comprising, in combination, alamp having electrical connections to a flanged base and to a terminalpin projecting from said base, said terminal pin being electricallyinsulated from said lamp base, a common terminal, a lamp mounting platehaving an opening for receiving and supporting said lamp base, meanselectrically connecting said lamp base to said common terminal, aspring, said spring being positioned on said lamp terminal pin, a baseplate having an opening for passing said lamp terminal pin whereby anend of said lamp terminal pin is in position to engage an externalcircuit connector, and means for releasably connecting said base plateto said mounting plate, said spring being compressed between said baseplate and said lamp when said base plate is connected to said mountingplate.
 15. A lamp assembly, as defined in claim 12, wherein said springis an elastomeric O-ring.
 16. A lamp assembly comprising, incombination, a lamp having electrical connections to a flanged base andto a terminal insulated from said base, a common terminal, a lampmounting plate having an opening for receiving and supporting said lampbase, means electrically connecting said lamp base to said commonterminal, a base plate, means for releasably connecting said base plateto said mounting plate, a headed terminal pin, said terminal pin beingpositioned in an opening through said base plate with said pin head inelectrical contact with said lamp terminal and wherein an end of saidterminal pin is in position to engage an external circuit connector, andat least one elastomeric ring positioned on said terminal pin, saidelastomeric ring being compressed between said terminal pin head andsaid base plate to urge said pin head into electrical contact with saiDlamp terminal.
 17. A lamp assembly, as defined in claim 16, wherein saidelastomeric ring is an O-ring.